The present invention relates to a process for preparing 1,3-dichloroacetone and epichlorohydrin.
It is known to prepare 1,3-dichloroacetone by the direct chlorination of acetone with chlorine. See, for example, U.S. Pat. No. 4,251,467. The process involves the use of iodine or iodine salts in greater than catalytic amounts. Iodine is very expensive ($13/kilo according to the Sep. 23, 2002 issue of The Chemical Marketing Reporter). For this reason, it is very important to recover and recycle the iodine or iodine salts in the process. The extra steps of recovering and recycling the iodine or iodine salts add significant complexity for building a commercially viable process for a commodity-type product. Another method for directly chlorinating acetone involves using methanol instead of iodine or an iodine salt. However, the major product of this process is the ketal of the chlorinated species. To get the 1,3-dichloroketone, one must hydrolyze the ketal which is not a trivial process.
It would be desirable to provide a process for preparing 1,3-dichloroacetone which would eliminate the need for using iodine and all the associated complexity of recovering and recycling it, as well as eliminate the need for hydrolyzing the ketal in the case of the latter method.